The 19-year-old McIlroy held a four-stroke lead going into the final round, but bogeyed two of the first three holes and then missed a five-foot putt for victory on No. 18 to settle for a 71. He then missed a 1-footer and made bogey on the second playoff hole before Lucquin holed a 12-footer for his first European Tour win in his 175th attempt.
Both players parred the 18th on the first playoff hole after missing birdie putts, Lucquin from 25 feet and McIlroy from 12 feet.
Lucquin shot a 67 to tie McIlroy at 13-under 271.
Miguel Jimenez (67), Gary Orr (67), Julien Clement (68) and Christian Cevaer (68) shared third at 12 under.